Pneumatic record sensing device



June 6, 1950 Filed Jan. 29, 1948 FIG. I Y

U I \x ,Y 39/ 369 .945 387 f 353 x L ,,393 y \377/ x 384 37; g FIG. 2

E /4/ I FHLVEgTORS arr 11 35/) 359 0. L Hibbfzrd i I BY L. 1 W F LMW F.M. CARROLL ET AL 4 Shets-Sheet 1 AT TOR N EY June 6, 1950 F. M. CARROLLETAL PNEUMATIC RECORD SENSING DEVICE 4 Sheets-Sheet 2 Filed Jan. 29,1948 INVENTORS F. M. Carroll 0. L .Hibbard )W ATTORNEY Nmm mmm

June 6, 1950 5 F. M. CARROLL ETAL 2,510,552

PNEUMATIC RECORD SENSING DEVICE Filed Jan. 29, 1948 4 Sheets$heet sINVENTORS F. M. Carroll 299 8 BY 0 L .H/bbard June 6, 1950 F. M. CARROLLEIAL 2,510,552

PNEUMATIC RECORD SENSING DEVICE Filed Jan. 29, 1948 4 Sheets-Sheet 4FIG. IO

INVENTORS f. M. Carroll BY 0 L Hibbard ATTORNEY Patented June 6, 1950PNEUMATIC RECORD SENSING DEVICE Fred M. Carroll, Binghamton, and OscarL. Hibbard, Johnson City, N. Y., assignors to Enternational BusinessMachines Corporation, New York, N. Y., a corporation of New YoApplication January 29, 1948, Serial No. 5,134

16 Claims. 1

This application is a continuation in part of our copending case SerialNo. 686,636, filed July 27, 1946.

This invention relates to record feeding and analyzing devices and moreparticularly to an advanced form of pneumatic sensing device forcooperation with perforated tabulating cards to repeatedly sense same ordifferent fields of perforated data in one of such cards.

An object of the invention is to provide im proved pneumatic sensingdevices for cooperation with perforated records, thereby making itpossible to sense such records without the usualcontact therewithincidental to the use of ieeler pins or electrical sensing brushes. Theobject is to construct the pneumatic controls with pressure and aforwardly directed vacuum action rather than a suction action, andthereby cause the lint, dirt, and other loose matter to be blown awayfrom the sensing unit and card and directed into an exhaust opening awayfrom all the sensing mechanism. Thus, the action produced is dual in acombined cleaning and reading operation.

The pneumatic action of the disclosed devices with air pressure in adirection toward an exhaust portv and away from the pneumatic unitexercises a useful scavanging action to clean the card at the same timethat it is sensed.

Another object of the invention is to provide a compact pneumaticsensing device for cooperation with perforated record material. Thesensing unit is designed to be fitted in 2. lim-- ited space by having adouble tiered arrangement of pressure chambers with a staggered array ofcylinders and pistons. This design makes it possible to have a largenumber of closely spaced air ports arranged side by side in a singleline, and yet extending from such ports are a series of cylinderopenings and pistons of substantial size leading to the air chambers andtubes for supplying the pistons with the activating air pressure andenabling a substantial electrical reading device to make contact undercontrol of the pistons. The piston or plunger is arranged to havecomparatively large clearance in the surrounding cylinder walls leadingto the port opening directly above the perforated record terial. The airpressure behind and in front of the piston is equalized as long as theadvancing record material. appears imperiorate under the air opening.However, as soon as a data representing perforation appears under theopening, the air on the record side of the piston escapes, creating; alow pressure area or vacuum under the piston head, thus causing the airon the intake side r of the piston head to exert enough pressure tocause it to move toward the sensing port. This motion is communicated toa flexed contact wire or blade which is then brought into electricalcontact with a common conducting bar.

Another object of the invention is to. provide pneumatic sensing deviceswherein the moving parts for establishing electrical contact are sosmall and light that they have a rapid operating cycle and fastrestoration movement in order that they will sense code perforations inadjacent index positions appearin in rapid succession under the airports.

Another object of the invention is the provision of a hollow recordholder to carry the record under analyzing devices, as shown, the holderis a hollow drum wherein the lint, dirt, paper threads, etc. from therecord may be blown oil and exhausted to, leave the record and thesensing area free from such matter as is likely to impair the properactuation of the sensing devices.

Fig. 1 is. an enlarged sectional elevation view through one pneumaticsensing unit.

Fig. 2 is an enlarged bottom View showing the air openings.

Fig. 3 is a side View of a pneumatic sensing unit.

Fig. 4-. is an end view of a pneumatic sensing unit showing the airintake port.

Fig. 5 is a plan view of a pneumatic sensing unit.

Fig. 6 is a side View of a sensing unit showing the side opposite thatshown in Fig. 3.

Fig. '7 is a sectional elevation View taken through the air valves whichadmit the compressed air to the two sensing units.

Fig. 8 is a projected plan view of the two air valves and the magnetcontrolled interposer operator therefor.

Fig. 9 is a projected plan View of the two valve operating interposersshown with the valves removed.

Fig. 10 is a sectional elevation view taken through the middle of thecard feed drum.

The invention is disclosed as embodied in an alphabet printing tabulatorof the kind shown generally in United States Patents 2,079,418 and2,199,547. These machines are controlled by perforated record cards andthe purpose is to accumulate separately the amounts represented bygroups of the records and also print bill forms or other accountingrecords. Heretofore, a plura ity of perforated cards, one for eachaddress line and one for each item, were needed to print a record suchas a bill. Now, instead of usin several separate cards for the relateddata, allmay be represented on one card and in different fields of saidcard and detected successively by passing the card repeatedly underpneumatic sensing means.

The air is driven through a filter by a pump and directed into an airpressure supply tank, and from there it passes two control valves VI,V2, Fig. '7, and along two hose branches into two pneumatic sensingunits U and L. These units correspond generally in position and purposewith the usual double line of electrical sensing brushes UB and LB foundin most tabulators and here replaced by the pneumatic units. Each unithas a row of air openings or ports which are aligned with the columns ofdata perforation positions of the record cards. The two sensing unitsare supported on an arcuate rockable frame which can be moved back forinspection, but is normally held with the two lines of ports over theperiphery of a hollow perforated drum D. A pile of cards are placed inthe magazine M from which they are picked off one at a time andtransferred to the drum D. The drum has clips for holding the cardthereon for about 180 of the drum movement, during which time the cardis passed under the upper unit U and then under the lower unit L beforebeing transferred to a stacker drum.

Upon the appearance of a card perforation under an air port (at a timedetermined by the location which is indicative of a particular letter ornumber value), air is allowed to escape into the drum D and, in sodoing, a piston in unit U or L closes related contacts. Unit U is usedas a control station for special heading card detection and group numbercontrol, while unit L has its contacts in series with add and printcontrol devices. The air blown into drum D with lint and dirt isexpelled through an exhaust pipe or hose leading away from central tubeI 86.

Cards with more than one field of data indicia have "a special digitperforation which is sensed as the card passes under the ports of theupper sensing unit U. Later, as the same card passes under the lowersensing unit L, devices under control of the special perforation reversethe motion of the drum D and rock it back and forth a number of timesdetermined by the magnitude of the digit.

The card guides Although the front end of each record card assembled onthe sensing drum D is held thereon by the grippers, the other portionsof the card are free and would tend to spring outward and abut againstvarious mechanisms near the periphery of the drum. To eliminate suchcard contact outside the drum area, a pair of arcuate card guides areprovided to confine the card path to a narrow arcuate space concentricwith the periphery of the drum. Two guides IT! and I'IB, Fig. 7, areproportioned to cover the areas between. the upper and lower sensingstation, and the area between the lower sensing station and stackingcontrol means respectively. Guide ITI is fixed to a pair of rods I13 andI'M extending across the space between the two side frames. The secondguide I78 is mounted in. a similar fashion between a pair of rods I15and I15 borne by the side frames.

The card carrying drum Drum D is a hollow cylinder, the ends of whichare closed by heavy annular rings I80 and IBI (Fig. secured to flangesjust inside the ends of the drum. The two rings are seated on the longperforated tube I86 which Q iQIidS t l'o g l and is affixed to both sideframes 42 and 43, the left end being solid and having an extending portion 89 beyond the outer surface of frame 42, and the right endextending beyond frame 43 to hold a hollow elbow It? to which isassembled the hose or exhaust tube to carry off the lint, dirt, etc.,blown through the perforations I 88 in the tube The tube IE6 is held inposition axially by means of a collar I89 held thereon by a set screwbetween frame 43 and a hub I953 on ring I8 I. The left end of tube I526passes through a bushing iEII on frame 42. Formed on the left end of thetube is a bearing shoulder I26 out of which extends the shaft 89 used asthe picker clutch shaft. However, movement of drum D is independent ofthe movement of clutch shaft 89. Tube I36 is held fixed and the drumrotates thereon by means of bearing rings I93 and I94 fixed to the inneropenings of end pieces I and NH.

The periphery of the drum D is divided into four arcuate segments, i.e., four areas between the sets of grippers I iI (Fig. 7). In each ofthese areas, the drum is perforated with columns and rows of openings,each of which corresponds to an index point on the record card. Sincethe card taken for purposes of illustration is the ordinary card,alphabet data is represented by a twelve hole code. To correspond withthe spacing of the card indicia representations, each of the four drumareas is perforated with eighty columns of holes I95 (Fig. 1) withtwelve regularly spaced holes in each column. In other words, betweensets of card grippers on drum D there are twelve holes I95 in an arcuateformation, and horizon= tally displaced across the drum are eighty suchformations. These drum perforations are so placed with respect to theset of grippers I4I which precedes them in the counterclockwisedirection that they match the location of all the card perforationpositions. Therefore, while a card is on the drum, underlying each ofthe card perforation positions is a drum opening to allow free passageof air under pressure through the card indicia perforations. On theother hand, all imperforate card index points cover all the other drumopenings and prevent air from being blown through them.

The card gripper operating mechanism It is already mentioned that thesensing drum D contains four sets of card grippers I4I, Fig. 7, whichare equally spaced around the drum to grasp the cards as they are issuedsuccessively out of the magazine M. Reference to the broken sectionalview (Fig. 10) shows three of the five grippers arranged across the drumin each set. Each gripper is rectangular in formation and projectsupward through a rectangular opening in the periphery of the drum, saidfive openings being slightly smaller than the heads I42 of the grippers.The lower part of each gripper MI is formed with a foot I9! which actsas a pressing point for one end of a pressure spring I98, the other endof which contacts with the inside of the drum.

All five grippers of a set are supported within an L-shaped formation2M3 extending across the inside of the drum D and providing slidingsurfaces for guiding the reciprocating movements of the five grippersMI. Extending across the entire drum and projecting through openings inthe end rings I89 and I8! of the drum is an operating bar 20I which isseen in Fig. 7 to be shaped in the form of a Z with a lower extensionunderlying all five grippers .1 of one set. It is through operation ofthe b r and this extension that t grippers are. lifted in unison toreceive a record card out of the magazine. Bar 2.0.! is also formed withan upper stopping protection which abuts against a shoulder on theangular formation 200. The bar is confined betweenv the abutting lug offormation 200 and the sides Of. the grippers Ml, but it is free forradial movement away from the center of the drum, and it is with suchmovement that the grippers are operated.

The four operating bars 201 are operated successively in two of thepositions assumed by the sensing drum as it rotates in card feedinopera-.-

tion. The one gripper operating position is that provided for receptionof cards as they come out of the magazine, and the other gripp r prating p sit on is at enc untered after sensin is completed under thetwo sensing units and the card is about to be put in the stacker.

c dfe 'd drum rotating m chanisms.

The card feed drum D is rotated and oscillated by means of pawlsengaging notched disks or ratchet wheels attached thereto. Certain ofthe pawls operate to. rotate the drum in the forward card feed directionas long as ordinary detail cards are presented. Other pawl mechanism isprovided to reverse the direction of the drum movement and oscillate ita selected number of times for heading or cross footing card control toread several selected number of fields of data or repeatedly sense onefield on each card. The reverse pawl mechanism is under control of aspecial heading digit perforation which is also by virtue of its value acycle control perforation for selecting a predetermined number ofdrumreversal operations, the number of reversalsneeded depending on thenumber of fields of information to'be recorded or added.

In Fig. 10, it is seen that attached to the left end of drum D is a setof three spaced ratchet disks or wheels 219, 228 and 221. Disk 220 isused for the reversal movement and the other two disks are used forinitial and terminal forward feed movement.

Sensing unit supports The sensing units U and L are mounted on aswinging frame which can be tipped back so that about one-half theperiphery of drum D may be exposed for cleaning and inspection.

Both main side frames 42 and is are formed with upwardly extending earsfor holdingthe sensing unit frame. Facing these cars and held thereto bya shaft is an ear (not shown) on a rockable frame member 343 which is aright side frame for the sensing units. Frame 343' and the companionframe on the left side are mounted in the same fashion on the main sideframes 42 and 63.

When the frames are rocked to the home position wherein the sensingunits are effective, a fiat portion of each frame rests on a shelfformed near the tops of the side frames. The sensing unit frames arelocked in place by a pair of latches pivoted on the outer faces of theframes. With the sensing units in the exposed position, access is alsogiven to the surface of drum D, so that all parts related to the sensingoperation can be inspected, cleaned and adjusted.

Reference to Fig. 7 shows that both pneumatic sensing units U and L areshaped generallyas rectangular bars of about the same length as drum D;and they are placed between the side frames to. correspond with theaxial position of the drum. {Since both units U and L are similarlyconstructed and mounted in the rockable frame, description of either oneapplies to the other.

Attached to, the right of unit; U is a hollow hose fitting- 340. Fig. 3,for receiving the flexible hose 3 Fi 7, which conveys the air- :underpressure from a pump to the sensing unit.

The. sensing units are suspended within, the rockahle, frame 342., 34.3by parallel links. which be operated to raise the units before thegripper heads hi2 pass underneath them. Normally, the sensing units arelowered into contact with the card surface which is moving in an rec-atepath. A virtual air seal is provided between. the. air Port openings andthe contacting card urface. However, while passing beyond the indexpoints near the mar in of the card at. the botto-nnand over to thcedgeofthe next card where the grippers v ngage it, it is not necessar topreserve the seal because the sensing air pressure is not then appliedand therefore. the. units may be lifted to Provide clearance for theripper heads.

Extending across the rock-able frame (Fig. Fl) .18 a pair of suspendingshafts 34.5 and 34S and a pair of Operating shaf s 3e? and. see forcontrollingthe lifting of; the units U and L. Attached to shafts 341,348 are. pairs of arms. 349. carrying rods .350 which are also encircledby cars. 35! extending from the sensing; units. iPivoted on the shafts345., 345, are the ends of a pair of links 35.2 which at the other endsencircle shouldered studs 353 extendin from the side walls of thesensing units. coil. spring wrapped around shaft 345 and confined by acollar thereon. Thespring is wound to exert rotary force and is caughton th top of link 352 to urge it and unit U downward in a clockwisedirection about shaft. 345. A similar spring is. assembled on shaft 3 46to urge unit L downward.

With pairs of links 3&2 and arms 349 as the supporting means, eachsensing unit is mounted for movement radially with respect to the centerof drum D. Springs tend to hold the units inward in. constant contact.with the card surface. Adjustably secured to. shafts 3.50 are pairs ofeccentric collars in contact: with the fixed support rods I13 and H5near the inner ends of the two sensingunits. These collars determine theexact inner positions of the units and the degree of: closeness theunits have with, or the required pressure upon, the card surface. Byturning the eccentric collars and fastening them in selected an ularpositions, the inner ends of the sensing units can be positioned asdesired on or above the card to eliminate excessive air leakage. An airpressure of from 3, to 10 pounds may be used with e#- as, a desirablevalue.

Although the springs tend to hold the sensing units in the effectivecard reading position, a positive disengaging means. is provided to liftthe units: together for a portion of eachcycle. Since the. units are.spaced exactly at a interval circumferentially of drum D, which isalsothe interval from card to. card thereon, an action for lifting oneunit for clearance of the gripper heads may be taken simultaneously withthe lifting of the other unit.

The. pneumatic sensing units Each of the sensing devices U and L may beconsidered as a unit, for it is removable for replacement andinspection. Units .U and L: are similar construction so that thedescription which.

follows applies to either structure. The purpose of th pneumatic unit isto direct separate jets of compressed air, one jet for each card column(80 in the disclosed embodiment) against the index point positions of amoving card. In all the imperforate positions of the card, the air isconfined and ineffective. However, as soon as a data representingperforation appears under a jet, the air escapes therethrough to pullwith a vacuum action on a piston in the stream of the air. Connected tothe piston are contact closing devices for sensing an electrical impulsewhich is timed to correspond with the data value which is determined bythe position of the perforation in the card column. In the case ofalphabetic data, two perforations are placed in code positions in asingle column to represent a letter, and two differentially timedimpulses are initiated by the same pneumatic sensing controls.

Figs. 1-6 show various views of a pneumatic unit. A number of barsextend th full length of the unit and :are assembled between side plates369 and 310 which are formed with the supporting cars 35! and carrystuds 353 for supporting links 352.

A set of four metal bars -31I-314 are fastened between the end plates369 and 310. These bars are accurately machined and fitted closelytogether with air tight joints because they are formed with tubes,cylinders and air chambers for carrying and confining air underpressure. The one central bar 312 is formed with a set of eighty grooveswhich, when the bars 312 and 313 are assembled face to face, are blockedoff to provide eighty rectangular port openings 316 (Fig. 2)corresponding in size and spacing to the arrangement of columns ofdata'perforations on the card. There is a port 316 for each column ofindex points on th card, and the unit is located to match the ports withthe card columns as they appear directly above the sets of openings I95in the drum D carrying the card. The lower ends of bars 312 and 313 arebeveled down to a smooth blunt end designed to ride on the surface ofpassing cards.

The top of each rectangular tube or port 316 (Fig. 1) is blocked off andsealed because the groove of which it is composed does not extend to thetop of bar 312.

Leading off from each of the vertical tubes 316 is a horizontalcylindrical opening 311 with constricted holes between the two. Thereare forty such openings 311 in bar 312 and they are arranged in two rowsand staggered in position along said rows. A similar number ofcylindrical openings 31'! are cut into bar 313 where they are alsoarranged staggered in two rows.

In each of the eighty openings 311, 311 is a piston comprising adisk-shaped piston head 319 and a long rigid piston rod 380 fastenedthereto. Attached to the ends of the rods 383 are insulation buttons381a, 3811), 38lc and 381d, which are designated differently todistinguish the rows and tiers of pistons and the order in which theyare arranged across the unit. It is apparent from the positions ofbuttons 38la38id that not only are the pistons arranged in four rows butthe rows are divided into two tiers wherein the pistons are reversed inposition, so that the buttons 381a and 38Ic of the two top rows ofpistons project at the right, and the buttons 38!!) and 381d of the twobottom rows of pistons project from the left of the unit. Rods 386 slidein holes in the bars to guide the pistons.

With the Pistons arranged as shown, it is possible to make the workingparts of substantial size and durable formation while leading to theport openings 316 which are necessarily of restricted size and closeformation as determined by the card index point and column proportions.

Behind the upper tier of pistons is an air inlet chamber 383 and thereis a similar chamber 384 behind the lower two rows of pistons. Chamber383 is formed by cutting a wide groove almost the entire length of bar31!, one end being sealed and that is the end near the side plate 310(Fig. 3). The other end of chamber 333 is not sealed, because plate 369(Fig. 4) is formed with a rectangular opening 383' leading into thetrapeziumshaped inlet hose fitting 340 which is clamped to plate 369.The other chamber 384 is formed in a similar fashion in bar 314 andcoincides with a hole 384' in plate 369 to communicate with the inneropening of the air hose fitting 340.

In chamber 383 (Fig. 1) there extends a shouldered end of the pistonassembly. This end abuts against the side wall of the chamber and actsas a limiting stop for the piston 319 which is spring urged toward theleft to the home position as shown.

Piston 319 is not fitted closely in the cylinder 311 but instead hasconsiderable clearance so that the air is allowed to flow from chamber383 to cylinder 311 and build up equalizing pressure in front of thepiston quite rapidly after the piston is actuated. In the normalcondition of the parts, with piston 319 positioned as shown, air undersubstantially equal pressure is present in chamber 383, behind thepiston in cylinder 311, in front of the piston, and all the way downtube 316 to the port obstructed by the surface of a card.- Should therebe a slight leak of pressure at the port due to an imperfect seal withthe card surface, such a drop in pressure would not be sufficientlyabrupt to cause piston actuation. However, when a data representing cardperforation appears under port 316, there is a sudden release of the airunder pressure through tube 316, the card and a drum opening I95.

The air in cylinder 311 and tube 316 in front of piston 319 is free tomove while the air in chamber 383 behind the piston is restricted inmovement by the presence of the piston. The result is that the airescaping through the card perforation causes a lowering of the pressurein front of the piston amounting to a vacuum or partial vacuum in thecylinder 311. For a moment this condition exists until the air behindthe piston tries to fill the lower pressure area and in so doing movesthe piston and the connected rod 386 toward the right.

As explained hereinafter, a contact establishing spring presses againstthe right end of the piston assembly, and it is this spring pressurewhich is overcome by the air under pressure. Movement of the piston tothe right is of sufiicient duration to establish contact before the airpassing around the clearance between the piston and the cylinder wallreaches the lower end of tube 316 and abuts against the card surface andtends to equalize the air pressure before and behind the piston. Whensuch a point of equilibrium in pressure is about to be reached andbefore it is reached, the spring urging the piston assembly to the leftbecomes effective to restore the piston and at the same time break thecontact which is established by movement toward the right.

It is necessary for the actuation of the piston and the resultingelectrical contact to be extremely rapid, because there are instanceswhen two perforations in a card column are found directly adjacent eachother, and separate impulses must be created by successive actuation oi.the piston under control of the two perforations appearing one rightafter the other on the rotating drum under the pneumatic port. For thisreason it is important that the size or area or the tube 316, the holesleading from the cylinder 31'! into the tube 376 and the clearancebetween the piston 37S and the walls of cylinder 3'11 be so proportionedthat the right amount of time is allowed to elapse between the actuationof the piston by the vacuum condition and the rapid resumption ofpressure equilibrium which follows thereafter. It was found byexperiment that the proportions between the area of the rectangular tubeopening 315 and the clearance area around the piston 379 should beapproximately as 3 is to 1. This proportion presupposes that there issufficient opening between the cylinder and the tube to allow freeescape of the air under pressure. The area of the piston head 319 isabout 15 times the area of the port opening 316. The area of pistonclearance is substantial so that, when multiplied by 1-2, it is aboutequal to the average volume of the air port chamber between the pistonand the card. It will be noted that the advantage lies not only in therapid initiation of an impulse upon the appearance of a card perforationbut alsothe rapid recovery of the impulse creating facilities, so thatrapid operations may continue under high speed conditions.

Now that the operation of the piston has been explained with referenceto the action of the air pressure thereon, it is believed well to pointout how such actuation is converted into the initiation of electricalimpulses which are timed by virtue of the positions of the relatedperforations in the card on the drum. Since the adding and printingdevices of the machine are synchronized with the operation of the drum,the resulting impulses are effective to control accumulation of theamounts sensed on the record card and the recording of numerical andalphabetic data also analyzed thereon.

Extending across the top of the electrical sensing unit is a pair ofsquare insulation bars 386 and 38'! fastened between the side plates3'69 and 310. These two bars are assembled at different levels, theupper one to cooperate with contacts controlled by the upper tier ofpistons and the lower one to have association with the other half of thepistons found on the lower level. The bottom portion of each insulationbar is slotted at regular intervals in forty places to receive and holda like number of L-shaped transmission plates 388. The verticalextension of these plates 388 are not of similar length but are seen tohave two different sizes, the short length extensions being interspersedwith the longer extensions the iormer provided for the upper row ofpistons of each tier. In contact with the horizontal member of each Lplate 338 is the p inted end 389 of a vertical terminal 390 pmjectingupward with plug openings at the upper surfaces of bars 388 and 381.

In Fig; 5 it is seen that these wiring terminals 390 are arranged in astaggered formation across the tops of the'two insulation bars. Theyactas receivers for plug tips on wires leadingfrom the control mechanismof the tabulator; Terminals 390 are formed hollow to receive the tipsand establish contact therewith.

Extending downwardly from each terminal plate' 3-88 is a leaf Spring 39]which at its lower end fits into a notch out vertically in the button3am fastened; to the end of the piston rod 380. Leaf spring 39! istensioned to press thepiston assembly toward the left into the normalposition,- wherein the left end of the assembly abuts against the leftwall of chamber 383.. The plates 388 formed with the long vertical.extensions also carry similar leaf springs 39! in the shape of a bentwire which cooperates with the other row of buttons SB'Ic fastened tothe second row of pistons in the upper tier. The plates iifiaproj'ecting from the left bar 2'87" are similarly provided Withleafsprings 39] cooperating with the buttons 38th and 381d on the lower tieroi .pistons.

Associated with the forty leaf springs 391 at the right is a commoncontact bar 392 fastened to plate 374 but separated therefrom by aninsulation strip 393. This bar is formed with a series of upper andlower prongs 394 and 395 extending inwardly toward the sides of 'theleaf springs 391 but normally separated therefrom. Electrical contact isestablished between the leaf spring 391 and prong 39E whenever thepiston '37!) is shifted to the right by change of air pressure attendingthe detection of the presence of a card perforation. The impulse pathflows through bar 392 out to prong 394 against the abuttifig lea'fspring '39] up into the terminal plate 333 and. thiO'ugh plug socket 3to the colltiOl Wi l'- me.

In order to explain the arrangement of the pistons and connected contactsprings more fully, certain Of the terminals 3 911 (Fig. 5) are furtherdesignated 39Ud-390d to point out that the succes'sive denominational orcolumnar orders of the sensing" device alternate from side to side ofthe unit a's'w'ell as being staggered in arrangement on each Side. It isseen that the 't'eiinihal 3911a is on the right side While the he'Xttermineu (i. e. he'xt with reference to lengitudihal distribution), ter:minal 39011, is on the left side, and the other two teflhifial's'iiQ'Oand 3'9Ud a1so alternate from right to left. It is explainedherei'r'ibefore that the buttons 3'8! d'38l (1' also alternate from sideto side as well as from tier to tier; Now the effect of such arran ementmay be Studied with reference to the electrical connections betweenspring wires or Contact blades 39'! and the prongs '394 and 95 on thecommon contact bars 392. The spaced and staggered buttons '38'la and3810 (Fig. '6) in the uppertier are seen to extend from the right walland operate wires to contact with prongs 39 i and 395, respectively;Similarly; the spaced and: stagg'ied' buttons 38117 and 3810? (Fig. 3)in the lower tierare round to extend from the left bar '3'? I' andoperate wires 39! to contact with the long and short prongs,respectively. From the foregoing it maybe gathered that the electricalcontact devices are made in s'turdier proportions and withgreaterclearances due to the piston arrangement in staggered rows andalterhatin'g tiers.

The pressure control values It is shown in Fig. '7 that a pair ofcontrol valves is provided between the compressed air supply and theupper and lower sensing units U and L. These valves cut oil thecompressed air at times when there are no cards atthe sensing stations;

A more detailed -showing or the valves and the operating mechanismtherefor is given in Figs. 7-, 8 and "9. valve V] is seen to cover theopening to thetube that leads from the'main air pressure inlet 33!" tothe se arate duct or tube 34] which is connected to the upper sensingunit U and conducts the air under pressure to the chambers 383 and 384in the unit housing. The other valve V2 is seen to be positioned toclose the valve opening of a cylinder which is the connector between themain air entry space 334 and the separate tube 344 that leads to the airchambers in the lower sensing unit L.

Valves VI and V2 are seated in a casing 354 secured to the rockableframe 343. The stems of the valves extend below the casing 354 (Fig. '7)and have formed thereon collars 358 against which press the ends of coilcompression springs 364 tending to keep the valves closed.

The lower ends of the valve stems are poised above a pair of bell cranks399 pivoted on studs 454 extending from a shelf 385 formed on a slide375 attached with a screw and slot connection 382 to the main slideframe 43. Slide 315 is articulated at 419 on the top of an operating arm45'! which is pivoted at 46! on the main frame and carrying a roller 458cooperating with a cam 462 fixed to shaft 16.

Early in each cycle, cam 462 rocks arm 46'! in a counterclockwisedirection and the arm then pushes slide 315 to the left so that thecranks 399 thereon press against the ends of the valve stems and liftvalves Vi and V2. In Fig. 9 it is seen that the long arms of cranks 399are normally directly under the stems of the valves and in position tooperate them as timed by cam 462 to agree with the perforation positionson the cards, said valves being closed at times other than the indexpoint sensing time.

Cranks 399 are used as interposers for disabling the valve liftingaction and thereby cutting off the air pressure supply to one or bothsensing units'for one or more complete cycles. This control is exercisedunder control of card levers for detecting the absence of cards at thesensing stations and thereby closing contacts to energize magnets forrocking cranks 399 to prevent valve operation when cards are missing.

In Fig. 9 it is seen that, if a. crank 399 is rocked about 30 in acounterclockwise direction, the long arm will be moved out of abuttingrelation with the end of the valve stem. Then, even though slide 375reciprocates the cranks axially, the one which has been rocked fails tooperate the related valve. The magnets for rocking the, interposercranks are about to be described.

Attached to frame 43 (Fig. 8) is a bracket 464 carrying a pair ofmagnets VIM! and VIM2, the former being controlled by the upper cardlever and the latter by the lower card lever. Associated with themagnets (Fig. 8) is a pair of armatures 4G5 pivoted at 414 on bracket464. A horizontal armature lever extends to the left and is articulatedwith the flat end 475 of a call rod 411, the lower end of which is bentto project into a hole in the short arm of crank 399. Ends 415 areguided by a notched bracket 418 and the lower ends are confined by aretaining strip 456 which is forced into grooves of studs 454 and servesto hold the cranks 399 down on the pivots with just enough room betweenthe bottom of strip 456 and the top faces of the cranks for the ends ofwires, ll"! to move freely to operate the cranks.

When a magnet is energized due to the absence of a record at the relatedsensing station, armature lever 465 (Fig. 8) is rocked clockwise andwire 41! is pulled upward to rock the crank 399 counterclockwise (Fig.9) and move the long arm thereof away from the end of the valve stem.Then, when the slide 315 is shifted upward, it is ineffective to causelifting of the related valve with the result that no air under pressureis supplied to the sensing unit having no card on which to work.

While there have been shown and described and pointed out thefundamental novel features of the invention as applied to a singlemodification, it will be understood that various omissions andsubstitutions and changes in the form and details of the deviceillustrated and in its operation may be made by those skilled in the artwithout departing from the spirit of the invention. It is the intentiontherefore to be limited only as indicated by the scope of the followingclaims.

What is claimed is:

1. In an accounting machine controlled by perforated records, apneumatic record sensing unit comprising a body structure with aplurality of closely spaced port openings cooperating with said recordperforations, said structure having separate cylinders at an angle toeach of said openings and connected therewith, a piston in each of saidcylinders, said structure having an air chamber leading into all of saidcylinders, means for supplying air under pressure to said chamber, andelectrical contact devices operated by said pistons when they move dueto the escape of air from related ports through said recordperforations.

2. A pneumatic sensing unit comprising a body structure with a pluralityof rectangular port openings spaced in a single row at regularintervals, said structure having a series of cylinders in a staggeredformation and connected to said openings, each cylinder communicatingwith a related port opening, said structure also having an air chamberleading into all of said cylinders, means for putting air under pressureinto said chamber, a piston in each of said cylinders, and electricalcontact devices operated by said pistons when they move due to escape ofair from related ports.

3. A pnenumatic sensing unit comprising a frame with a plurality of airport openings arranged at spaced intervals, said structure also having aseries of cylinders each of which is in communication with a relatedport opening, means for compressing air in said cylinders, a piston ineach of said cylinders, a piston rod extending from each of said pistonsand extending through said frame to the outside, and electrical contactdevices operated by said extending piston rods.

4. The invention set forth in claim 3, wherein said electrical contactdevices comprise a series of individual terminal plates, each of whichcar ries a flexible contact member, said member being in cooperationwith one of said piston rods and a common contact bar also on theoutside of said frame, said bar having a portion normally separated fromsaid flexible members, whereby operation of any of said pistons causesmovement of the related flexible member into contact with said commonbar.

5. The invention set forth in claim 3, further characterized by the factthat a substantial amount of clearance is provided between said pistonand the walls of the surrounding cylinder, the proportion of saidclearance area to said port opening being as l is to 3, whereby saidpiston is restored quickly upon the escape of air from the port opening.

6. The invention set forth in claim 3, further characterized by the factthat the area of the piston is substantially larger than the portopening, the ratio being approximately as 15 is to 1, whereby escape ofair through a port opening causes rapid actuation of the piston andconnected electrical devices.

7. A pneumatic sensing unit comprising a frame with a plurality of airport openings spaced at intervals, said structure having a plurality oftiers of cylinders at an angle to said openings, each cylindercommunicating with a related port opening, means connected with saidframe for placing air under pressure into said cylinders, a piston ineach of said cylinders and electrical devices operated by said pistonsupon the escapement of air from the port openings.

8. The invention set forth in claim 7, further characterized by the factthat the different tiers of said cylinders are arranged on oppositesides of said frame and in opposite directions to the port openingsarranged in a single centralized row.

9. The invention set forth in claim 7, characterized by the fact thatsaid different tiers are arranged at different levels on opposite sidesof said frame and project from the centralized port openings indifferent directions and at diiferent heights from the openings thereof.

10. The invention set forth in claim 7, further characterized by thefact that said tiers each comprise a plurality of staggered rows ofcylinders, said tiers being arranged not only on opposite sides of saidframe but also at different levels, whereby the row of port openin s cmmuni ate with cylinders on both sides of the frame at different levelsor tiers and rows of cylinders arranged in staggered formation withinthe tiers.

11. The invention set forth in claim 7, characterized by the fact thatthe cylinders in said plurality of tiers are arranged in a staggeredformation therein and said tiers are placed on opposite sides of saidframe at different levels and further characterized by the fact that theport openings are connected thereto alternately with one port openingcommunicating with a, cylinder in one tier and the next port openingcommunicating with a cylinder in the other tier.

12. The invention set forth in claim 7, characterized by the provisionof four rows or cylinders arranged in two tiers, the two rows ofcylinders in each tier being arranged in a staggered formation therein,said tiers being arranged with the cylinders on opposite sides of saidframe and at different levels therein, said port openings communicatingwith said four rows of cylinders alternately with respect to thedifierent tiers and rows, whereby a space is provided for each cylinderopening four times that of the space provided for each port opening.

13. A pneumatic sensing unit having a. frame composed of fourrectangular bars connected to form a single unit, one of the inner orcentralized pair of said bars being formed with a series of facinggrooves to form a row of port openings, said centralized pair of barsalso being formed with a plurality of tiers of circular openingsarranged in staggered formation at right angles to said port openinggrooves and communicating therewith to furnish individual cylinders forthe port openings, the two outer pairs of bars being formed with innerlongitudinal grooves comprising air chambers communicating with allcylinders, means for supplying air to said chambers, pistons in saidcylinders, and electrical devices operated by said pistons when air isallowed to escape through any of said port openmgs.

14. The invention set forth in claim 3, characterized by the fact thatthe electrical contact devices include a flexible member in cooperationwith said piston rod to force an extending end of said piston into anabutting relation with a wall of said frame, whereby the electricalcontact de vice serves a dual purpose in restoring said piston andestablishing contact.

15. In a machine controlled by perforated paper sheets, a pneumaticsensing unit contacting the surface of said sheets, means for advancingsaid sheets with respect to said sensing unit, said sensing unitcomprising a frame structure formed with a plurality of port openingsending directly on the surface of said sheet, said frame also formedwith a plurality of cylinders each communicating with one of said portopenings, a piston in each of said cylinders, an air chamber in saidframe, means for supplying air under pressure to said chamber and insaid cylinders behind said pistons so that the appearance of theperforation causes the escape of air and the movement of a relatedpiston toward the port opening, electrical contact devices operated bymovement of the pistons whereby the movement of the air away from thepistons and contact devices causes the removal of lint and dirt in adirectlon away from the mechanism.

16. The invention set forth in claim 3, further characterized by thesubstantial area of clearance provided between the piston and thecylinder ,said clearance area multiplied by 12 being equal to theaverage volume of the port space between the piston and the air portopening.

FRED M. CARROLL. OSCAR L. HIBBARD.

REFERENCES CITED The following references are of record in the file ofthis patent:

